Adjustable stabilizer for boats

ABSTRACT

A stabilizer device for boats to maintain a boat in a substantially horizontal position during forward movement of the same and to resist tilting, rolling or bobbing movements of the boat due to wave action. The stabilizer device includes platelike means attached externally to the stern of the boat to form an extension of the bottom surface thereof against which the water may exert an upward force tending to lift the stern of the boat thereby resisting the tendency for the stern to be depressed and the bow to rise when the boat moves forwardly in the water. Means is provided forming an adjustable, yieldable connection between the platelike means and boat at a location to yieldingly resist upward movement of the platelike means and to permit vertical adjustment of the same to regulate the stabilizing action of the water on the device.

United States Patent [72] Gerald J. Curtis 8806 Glen Loch, Houston, Text. 77017 [21] Appl. No. 793,012 [22] Filed Jan. 22, 1969 [45] Patented Feb. 23, 1971 [54] ADJUSTABLE STABlLIZER FOR BOATS 4 Claims, 8 Drawing Figs. 7 [52] 11.8. C1 114/66.5 [51] Int. Cl 1363b H22 [50] Field ofSearch ll4/66.5P

[56] References Cited UNITED STATES PATENTS 2,985,130 5/1961 Jacobs et al. 1l4/66.5 3,046,928 7/1962 Sherrill 1 14/665 3,058,442 10/1962 Curtis 114/665 Inventor 3,062,167 11/1962 Bennett 3,200,782 8/1965 Waldenetal ABSTRACT: A stabilizer device for boats to maintain a boat in a substantially horizontal position during forward movement of the same and to resist tilting, rolling or bobbing movements of the boat due to wave action. The stabilizer device includes platelike means attached externally to the stern of the boat to form an extension of the bottom surface thereof against which the water may exert an upward force tending to lift the stern of the boat thereby resisting the tendency for the stem to be depressed and the bow to rise when the boat moves forwardly in the water. Means is provided forming an adjustable, yieldable connection between the platelike means and boat at a location to yieldingly resist upward movement of the platelike means and to permit vertical adjustment of the same to regulate the stabilizing action of the water on the device.

PATENTED FEB23 19m SHEET 1 OF 3 Gare/a J (off/J INVENTOR.

ATTORNEY BACKGROUND OF THE INVENTION In the operation of boats and particularly boats which are propelled at considerable speeds, such as racing boats, there is a tendency for the bow of the boat to rise out of the water to a height which increases with the speed of the boat. When operated in rough or choppy water, there is also a tendency for such boats to bob, the bow of the boat rising and falling rapidly so that there is danger of damage due to violent impact of the boat with waves.

The operation of boats of this character is often impairedby irregularities in the shape of the hull resulting from warping or other imperfection which may produce an unbalanced condition likely to cause listing or rolling of the boat.

Various expedients for overcoming these disadvantages have proposed heretofore, such as by the provision of plates extending rearwardly from the stern of the boat to form extensions of the bottom surface of the boat and having surface portions positioned to eoact with the water to stabilize the motion of the boat. Such devices, as heretofore provided, are commonly positioned by trial and error without adequate means for adjustment to vary the effect of water thereon at different speeds of operation of the boat or under varying wave conditrons.

SUMMARY OF THE INVENTION Briefly described, the stabilizer or trimming device of the invention comprises a platelike member attached externally to the stern of a boat extending rearwardly therefrom to form an extension of the bottom surface of the boat in or near the plane of the bottom and against which the water may exert an upward force tending to resist the depressing of the stern'and the elevation of the bow of the boat dueto forward movement of the boat. The platelike member is attached to the boat by means which allows the plate to be adjusted vertically by flexing or hinging to vary the position of the plate to regulate the stabilizing effect of the water on the boat. Yieldable means is also provided forming a connection between the boat and plate member above the member and at a location on the member to yieldingly resist upward movement of the plate under the influence of the upward forceexerted thereon by the water, whereby the platelike member is automatically adjusted to vary the stabilizing'effect in accordance with rapidly varying conditions such as those resulting from choppy water or wave action.

BRIEF DESCRIPTION OF THE VIEWS'OF THE DRAWINGS FIG 1 is a diagrammatic view illustrating the invention and showing the manner in which the stabilizer functions when applied to a boat;

FIG 2 is a fragmentary side elevational view of the stern portion of a boat, showing the stabilizer of the invention attached thereto and illustrating the manner in which the same operates, the stabilizer being shown in dashed lines in a number of the different positions which it'occupies during the operation of the boat;

FIG 3 is a rear and elevational view of a boat showing the stabilizer of the invention attached thereto;

FIG 4 is a vertical, central, longitudinal, cross-sectional view, on an enlarged scale of a preferred embodiment of the invention, showing details of construction of the same, the device being shown in its downmost position of movement;

FIG 5 is a view similar to that of FIG 4, showing the stabilizer of the invention is an upper position of its movement;

FIG 6 is a rear end e'levational view of a boat, similar to that of FIG 3, showing a modified form of the stabilizer of the invention applied thereto;

FIG 7 is a vertical, central, longitudinal, cross-sectional view, similar to that of FIG 4, illustrating the modified form of the invention as shown in FIG 6, the stabilizer being shown in its downmost position; and

FIG 8 is a view similar to that of FIG 7, showing the stabilizer in its upmost position.

DETAILED DESCRIPTION OF'A PARTICULAR EMBODIMENT OF THE INVENTION The stabilizer of the invention is attached to the stern of a boat B, which may be a boat of any convenient type, such as one having the usual transom T at its rear end, two such stabilizers being ordinarily used, as seen in FIGS. 3 and 6. one on each side of the longitudinal center line of the boat. The stabilizers extend rearwardly from the stern of the boat and include platelike members having planar surfaces extending generally horizontally rearwardly in or nearly inthe plane of the bottom of the boat.

As illustrated in FIGS. 4 and 5, each of the stabilizers has a flexible, platelike member 10, preferably formed of sheet metal, of generally rectangular configuration, provided along one side with an upturned flange 12 for attachment to the transom T against the outer face thereof.

At its outer extremity the member 10 is formed with a tubular portion 14, through which a pin 16 is'pivotally extended to pivotally connect the lower end of a connector element 18 thereto, centrally of the width of the member. The upper end of the connector 18 is internally threaded for the connection thereto of the lower end of a shaft 20 which extends upwardly 'e'xteriorly of the transom T. The shaft'20 may be provided with a locknut 22 to be engaged with the upper end of the element 18 to prevent unscrewing of the shaft.

I The shaft 20 passes upwardly through a tubular adjuster sleeve 24, which is externally threaded for threadable adjustment in an internally threaded, outer tubular housing 26 which is pivotally connected to a perforated bracket 28, secured externally to the transom, as by means of a perforated lug 30 on the housing near its upper end, through which a pivot pin 32 is extended through the perforation of the bracket.

The adjuster sleeve 24 is formed at its upper end with an internal annular flange forming an internal upper end seat 34 for a yieldable member, such as the coil spring 36, whose upper end is seated on the seat 34 and whose lower end is seated on a washer or pin 38affixed to the shaft 20, mediate the ends of the shaft and which is movably disposed in the sleeve for longitudinal movement therein with the shaft.

The shaft 20 is threaded at its upper end portion to receive an adjusting nut 40, threadably carried thereon and which may be externally knurled or fluted to be easily rotated by hand.

In adjusting the stabilizer thus applied to the boat, the nut 40 may be threaded downwardly on the shaft 20 to a position to engage the upper end of the housing 26 to limit the downward movement of the shaft 20 in the housing and the adjuster sleeve 24 may be turned in a direction to back the same out of the housing to apply any desired compressive force to the spring 36'between the upper seat 34 and the lower seat 38. By suitably adjusting the sleeve and nut, the plate member 10 may be moved to any desired position of adjustment relative to the plane of the bottom of the boat, such as the downwardly curved position shown in FIG 4, in which position the plate member will then be yieldingly held against upward movement by the spring 36.

When the stabilizer is thus adjusted, the-nut 40 will engage the upper end of the housing 26 to limit downward movement of the shaft 20, while the plate member 10 will be free to flex upwardly in response to variations in the upward pressure exerted against the plate by the water as the boat moves forwardly therethrough.

The action of the stabilizer of the invention in stabilizing the movement of a boat is illustrated diagrammatically in FIG 1, wherein the usual position assumed by a boat moving forwardly in the water is shown in the upper view, the bow of the boat tending to rise out of the water to an increasing extent as the speed of the boat is increased. With the stabilizers of the invention applied to the boat, and properly adjusted, as described above, the upward pressure of the water against the stabilizers tends to prevent the upward tilting movement of the boat and to maintain the boat in a more nearly horizontal position during its forward movement, as seen in the middle view of FIG 1. Under conditions in which the stabilizers may be subjected to excessive upward pressure by the water, such as may occur when operating the boat in choppy water or at high speeds where waves are frequent, the plate members may flex upwardly to reduce the upward force of the water tending to tilt the boat, while the boat is passing over the waves, as seen in the lower view of FIG 1, thus stabilizing the motion of the boat and preventing excessive bobbing of the same.

The stabilizing action of the stabilizer of the invention is further illustrated in FIG 2, wherein the position which the platelike member may assume in response to an increase in the upward pressure of water caused by wave action, is shown in solid lines, while positions to which the member may be moved in response to successive variations in such wave action pressure are shown in dashed lines. Thus, as the upward pressure of the water against the plate member increases beyond the downward pressure to which the spring 36 has been adjusted, the plate will be flexed upwardly by compression of the spring, and the plate member will again be flexed downwardly by the spring as the upward pressure of the water falls off, to maintain the stability of the boat.

It will also be apparent that the stabilizers will respond similarly to conditions tending to cause rolling motion of the boat such as wave action or movement of the boat in a curved path, to prevent or lessen such rolling motion.

A modified form of the invention is illustrated in FIGS. 6, 7 and 8, wherein the stabilizer mechanism includes a generally rectangular supporting bracket 42 of angle shape in cross section having a flange 44 adapted to be attached externally to the transom T and a platelike portion 46, which extends rearwardly from the transom, and whose lower face is disposed substantially in the plane of the bottom of the boat. The support bracket may be shallowly recessed to receive the generally rectangular flexible, platelike member 10', which has an upwardly extending flange 12 disposed between the transom T and the flange 44 of the bracket and which is attached to the bracket, and a rearwardly extending portion 48 extending beneath the portion 46 thereof.

The support bracket may be provided with a central reenforcing gusset 50 extending upwardly between the portions 44 and 46, and has a slotted opening 52 in the portion 46 and upwardly extending perforated lugs, such as that shown at 54 on each side ofthe opening.

A bellcrank or lever member 56 is pivotally mounted on the bracket 42, as by means of a pin 58 or the like, located mediate the ends of the lever and extending through the perforations of the lugs 54. The bellcrank 56 has one arm 60 thereof which extends downwardly through the slot 52 and whose free end is rounded for engagement with the portion 48 of the flexible plate 10 to flex this portion downwardly away from the bracket upon rotation of the crank in one direction, as seen in FIG 7, and to allow the portion 48 to flex upwardly toward the bracket, as seen in FIG 8, when the crank is rotated in the other direction.

The other arm 62 ofthe bellcrank 56 extends above the portion 46 of the bracket and is connected at its outer end to a chain 64, or other suitable flexible element, extending upwardly into a hollow housing 66 attached externally to the transom T.

Within the housing 66 the chain 64 is connected to a coil spring 68, as by means of an elongated U-shaped connector link 70 having outwardly and downwardly turned portions 72 on the free ends of its arms which are hooked over the upper end coil ofthe spring.

A similar link member 74 is connected to the lowermost coil of the spring 36 and to a chain 76 which extends upwardly from the spring for releasable connection to a slotted bracket 78 having an open ended slot into which a link of the chain may be inserted. By pulling upwardly on the chain 76 the spring 36' may be compressed to exert an upward pull on the arm 62 of crank 56 whereby the portion 48 of plate 10' will be flexed downwardly by the arm 60, as shown in FIG 7. When the plate has been thus flexed downwardly to the desired extent, the chain is extended into the slot of bracket 78 to hold the plate in its adjusted position.

Suitable stop means, such as the screw 80, threadably adjustable in an internally threaded opening in a lug 82 on the support bracket may be provided, which is engageable with an abutment face 84 on the crank 56 to limit rotation of the crank in a direction to flex the plate 10' downwardly.

The operation of this modified form of the invention is similar to that of the form illustrated in FIGS. 4 and 5, the portion 48 of platelike member 10' being positioned for engagement with the water to transmit upward force exerted by the water against the plate to the stern of the boat to stabilize the boat. The upward flexing movement of the plate is limited by its engagement with the portion 46 of the support bracket 42 while downward flexing of the plate is limited by engagement ofthe screw with the abutment face 84 of the crank 56.

In either form of the invention it will be apparent that the stabilizers may be separately adjusted to compensate for irregularities or imperfections in the shape of the boat to bring the boat to a balanced condition laterally, whereby listing or rolling of the boat due to warping of the hull or other defects may be prevented.

It will also be noted that the downward force exerted on the platelike member to yieldingly resist upward movement of the member by the upward force ofthe water may be regulated as desired by adjusting the compression of the spring 36 or 36', while the amount of upward movement of the platelike member in response to the upward force ofthe water is limited by the nut 40 or by the stop screw 80.

The platelike member of the invention may, if desired, be hingedly connected to the boat for vertical swinging movement, such as by providing a hinge between the upwardly extending flange and the rearwardly extending portion of the member.

It will thus be seen that the invention, constructed and applied as described above, provides a boat stabilizer device which is of simple design and rugged construction, which is adjustable to regulate the stabilizing effect of the water thereon as the boat moves in the water, and which automatically adjusts itself to accommodate the rapidly varying conditions caused by operation of the boat in choppy water or waves.

The invention is disclosed herein in connection with particular embodiments of the same which are intended by way of illustration and it will be understood that various changes can be made in the construction and arrangement of the parts within the spirit of the invention and the scope of the appended claims.

lclaim:

1. in a stabilizer for boats a platelike member adapted to be movably connected to the transom ofa boat with a planar portion of the member extending rearwardly therefrom for angular movement about an axis extending transversely of the boat in position for contact with the water to apply an upward force to the transom,

an elongated element hingedly connected at its lower end to and extending upwardly from the member at a location spaced rearwardly from the transom,

connecting means pivotally mounted on the transom for vertical rocking movement thereon and through which said element is slidably extended,

spring means surrounding said element, and

threadable means on said element and said connecting means positioned for coaction with said spring means to adjust the resistance of said spring means to upward movement of said planar portion.

2. The stabilizer as claimed in claim 1, wherein said member is flexible.

3. The stabilizer as claimed in claim 1 including means positioned for coaction with said member and transom to limit downward angular movement of said planar portion.

4. in a stabilizer for boats, a platelike member adapted to be movably connected to the transom of a boat with a planar portion of the member extending rearwardly therefrom for angular movement about an axis extending transversely of the boat in position for contact with the water to apply an upward force to the transom,

a bracket adapted to be secured to the transom and having a portion extending rearwardly from the transom above said planar portion, 7

means rotatably mounted on the bracket for vertical rotational movement, v

yieldable means positioned for coaction with said rotatable means and member to yieldingly resist movement of said planar portion toward said rotatable means, and

means forming an adjustable connection between said member and said rotatable means to limit movement of said planar portion away from said rotatable means. 

1. In a stabilizer for boats a platelike member adapted to be movably connected to the transom of a boat with a planar portion of the member extending rearwardly therefrom for angular movement about an axis extending transversely of the boat in position for contact with the water to apply an upward force to the transom, an elongated element hingedly connected at its lower end to and extending upwardly from the member at a location spaced rearwardly from the transom, connecting means pivotally mounted on the transom for vertical rocking movement thereon and through which said element is slidably extended, spring means surrounding said element, and threadable means on said element and said connecting means positioned for coaction with said spring means to adjust the resistance of said spring means to upward movement of said planar portion.
 2. The stabilizer as claimed in claim 1, wherein said member is flexible.
 3. The stabilizer as claimed in claim 1 including means positioned for coaction with said member and transom to limit downward angular movement of said planar portion.
 4. In a stabilizer for boats, a platelike member adapted to be movably connected to the transom of a boat with a planar portion of the member extending rearwardly therefrom for angular movement about an axis extending transversely of the boat in position for contact with the water to apply an upward force to the transom, a bracket adapted to be secured to the transom and having a portion extending rearwardly from the transom above said planar portion, means rotatably mounted on the bracket for vertical rotational movement, yieldable means positioned for coaction with said rotatable means and member to yieldingly resist movement of said planar portion toward said rotatable means, and means forming an adjustable connection between said member and said rotatable means to limit movement of said planar portion away from said rotatable means. 